Direction change device

ABSTRACT

A direction change device includes first and second transport passage  3, 4,  in which one of the transport passages is disposed at the same vertical position as that of the first transport rail  16,  the other is disposed below the one, a rotating unit  22  rotating the transport passages  3, 4  about their central points, a lift unit  23  lifting the transport passages  3, 4  in a vertical direction and a control unit  21.  The control unit  21  controls such that when the FOUP  5  is carried out from the transport rail 16 to the transport passage disposed at the same vertical position as that of the transport rail  16,  rotating the transport passages  3, 4  by about 90°, carrying out the FOUP  5  from one of the transport passages, and exchanging the respective vertical positions of the first and second transport passages  3, 4.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a direction change device which changes a transporting direction of an article.

2. Description of Related Art

As a changing means used in semiconductor manufacturing, liquid crystal manufacturing, factory automation (FA), and the like, a transport system disclosed in Japanese Patent Unexamined Publication JF-T-2003-506289 is exemplified. In the transport system disclosed in JP-T-2003-506289, rotating wheels are provided so as to be projected from upper surfaces of a pair of rails, and an article placed on the wheels is transported along the rails by rotation of the wheels. Additionally, in JP-T-2003-506289, in a rail provided so as to be perpendicular to each other, a director drive rail which changes direction of the article is provided. The director drive rail is provided so as to rotate between two rails perpendicularly disposed to each other and can change the direction of the article by rotation of the article placed on the wheels.

However, according to JP-T-2003-506289, when the direction of the article is changed, once the direction change operation is ended, the article which newly comes from the transport rail cannot be changed the direction thereof until the director drive rail rotates and comes back the initial location. As a result, since the director drive rail is required to come back the initial location at each time of the direction change, the article cannot be transported while the waiting time.

SUMMARY OF THE INVENTION

An advantage of an aspect of the invention is that it provides a direction change device capable of shortening a changing time.

In order to achieve the above-mentioned advantage, according to an aspect of the invention, there is provided a direction change device which changes transporting direction of a work carried out from a transport rail, comprising:

first and second transport passages that has a straight-line shape, and are disposed so that they intersect each other with a right angle and central points thereof are on the same vertical line;

a rotating unit that rotates the first and second transport passages about the central point;

a lift unit that lifts the first and second transport passages in a vertical direction; and

a control unit,

wherein a vertical position of one of the first and second transport passages is made the same as that of the transport rail, and other of the first and second transport passages is made lower than that of the one of the first and second transport passages, and

the control unit controls such that:

-   -   carrying in the work from the transport rail to one of the first         and second transport passages of which vertical position is the         same as a vertical position of the transport rail,     -   rotating the first and second transport passages about 90°;     -   carrying out the work from the one of the first and second         transport passages; and     -   exchanging the vertical positions of the first and second         transport passages each other.

In such a configuration, after the direction of the work is changed to carry out the work, the next work can be ready to change the direction thereof in a short time. Specifically, by equalizing the vertical positions of the first transport passage and the transport rail and disposing the second transport passage below the first transport passage in a vertical position, the work on the transport rail can be carried out to the first transport passage without obstructing the second transport passage. Additionally, when the work is carried out from the transport rail to the first transport passage, the transporting direction of the work can be changed by 90° by rotating the first and second transport passage by about 90°. After the work is removed from the first transport passage, the work on the transport rail can be carried out to the second transport passage by exchanging the respective vertical positions of the first and second transport passages.

That is, when only one transport passage is provided in the rotating unit, it is necessary to move the transport passage back to a position where it can receive the work from the transport rail after the work is removed from the transport passage. However, as described above, by exchanging the respective vertical positions of the two transport passages, it is possible to shorten an idle time.

Additionally, according to a second aspect of the invention, as set forth in the first aspect of the invention, it is preferable that the transport rail and the first and the second transport passages have a plurality of rollers along with both sides thereof, and

the work placed on the rollers is transported by rotation of the rollers.

Thus, the work placed on the rollers can be transported by rotation of the rollers,

In such a configuration, since the work is transported by rotation of the transport rail and the rollers provided along both sides of the transport passages, the work can be transported without interrupting the transporting direction of the work.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematic top plan views of a direction change device according to the embodiment of the invention.

FIGS. 2A and 2B are schematic top plan views of the direction change device according to the embodiment.

FIGS. 3A to 3D are schematic side views of the direction change device according to the embodiment.

FIG. 4 is a partly schematic view of a transport system according to the embodiment.

FIG. 5 is a schematic view of a transport rail used in the transport system shown in FIG. 4.

FIG. 6 is a block diagram of the direction change device.

FIG. 7 is a diagram showing a data table.

FIG. 8 is a flow chart showing process routines for a direction changing operation.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION EMBODIMENTS

Hereinafter, an embodiment suitable to the invention will be described with reference to drawings. A direction change device according to the embodiment can be suitably applied to a transport system which transports an object along a transport rail in a step or between steps to manufacture a final product while processing the object like facilities of manufacturing a semiconductor product. A transport system which transports objects such as a substrate of a semiconductor, a glass substrate for a liquid crystal display, a glass substrate for a photomask, a substrate for an optical disk to manufacture an object, and a semiconductor, will be described. However, the transport system is not limited to such objects and can be applied to all types of transport systems transporting parts of an electronic apparatus, parts of a machine, chemical products, food, paper, or the like.

The semiconductor refers to a plurality of semiconductor wafers (not shown) retained in a cassette called a front opening unified pod (FOUP) shown in FIG. 5, for example. FOUP has an approximate cube in shape with two trimmed parts. The semiconductor is transported in the unit of the cassette and a predetermined process is performed in each processing device 15 described below. A transported object transported on a transport rail 10 is called an FOUP 5 (work) in the following description.

As shown in FIG. 4, the transport system has a plurality of the processing devices 15, the transport rail 10 transporting the FOUP 5 to each of the processing devices 15, a direction change device 1, and a control device (not shown) controlling the entire transport system. The transport system has a plurality of bays including the plurality of processing devices 15, and when a process ends in one bay, the FOUP 5 is transported to the next bay.

The processing device 15 includes a device for forming a thin film on a wafer, a device for cleaning, adjusting, and measuring the wafer, a device (so-called “stocker”) for storing the wafer, and the like. Each processing device 15 has a carry in ports 15 a at an entry and exit the FOUP 5 transported on the transport rail 10 is inserted by the carry in port 15 a to insert a received semiconductor into the processing device, or a semiconductor processed is stored in the FOUP 5 to be or able to be carried out to the transport rail 10.

The transport rail 10 is a rail transporting the FOUP 5 from the processing device 15 to another processing device 15 or the next bay. For example, as shown in FIG. 5, the transport rail 10 has a pair of rails 11 and 12 which are separated by a width so as to support the lower surface of the FOUP 5 and a plurality of rollers 13 projecting from each upper surface of the rails 11 and 12. The rollers 13 are disposed along the length direction of the rails 11 and 12 at a nearly equal interval and rotate in a regular direction. The FOUP 5 placed on the rollers 13 moves in a rotation direction of the roller 13 by rotation of the rollers 13.

Additionally, a drive motor for driving the rollers 13 independently operates in each bay. In such a configuration, since a rotation speed of the rollers 13 is changed in each bay, a transport speed of the transported FOUP 5 can be changed. That is, the transport speed of the FOUP 5 can be changed depending on the bay in which a process time varies at every processing step. Further, when many FOUPs 5 are transported in the next bay, the transport speed of the FOUP 5 can also decrease by decreasing the rotation speed of the rollers 13, the transporting number of the FOUP 5 can decrease in the next bay, thereby preventing overpopulated FOUPs 5 from being placed in the bay.

It is desirable that the rails 11 and 12 of the transport rail 10 (not shown) are forwardly projected along the edges of the transport rail 10. The projection parts serve as a transport guide, and this transport guide prevents transported the FOUP 5 from being departed in the horizontal direction.

A direction change device 1 is a device for changing the transporting direction of the FOUP 5. As shown in FIG. 4, the direction change device 1 is provided in an intersection portion in which two transport rails 10 or more intersect to change the transport direction of the FOUP 5. The intersection portion can be a crossed portion with four directions, a “T-shaped” intersection with three directions, a vertical intersection portion, or an intersection portion in which the transport directions of the transport rails or more are perpendicularly formed each other. As shown in FIG. 1, the direction change device 1 which is disposed on the “T-shaped” intersection with three directions having a first transport rail 16, a second transport rail 17, and a third transport rail 18 will be described. Specifically, the first transport rail 16 and the second transport rail 17 constituting the “T-shaped” intersection with three directions are disposed in a straight line, the third transport rail 18 is disposed vertically to the first transport rail 16 and the second transport rail 17, and the direction change device 1 is disposed in the intersecting part of three transport rails 16, 17 and 18. The transport rails 16 and 17 transport the FOUP 5 in an upward direction of the drawing and the transport rail 18 transports the FOUP 5 in a left direction of the drawing.

As shown in FIG. 1, the direction change device 1 has a turn table 2 (rotating unit), and a first transport passage 3 and a second transport passage 4 which are provided in the turn table 2 and intersect in a crossed portion each other in top view. The turn table 2 has an approximate cylinder in shape and the central axis serves as a rotation axis to rotate at an interval of 90° in a regular direction (an arrow direction of the drawing). The first transport passage 3 has a plurality of a pair of rollers 3 a, which is separated by the width equal to the width between the rollers 13 provided in the rails 11 and 12 of the transport rail 10, on the straight line. The FOUP 5 placed in the rollers 3 a is transported by rotation of the rollers 3 a. Additionally, the second transport passage 4 has a plurality of a pair of rollers 4 a on the straight line similarly to the first transport passage 3. The first transport passage 3 and the second transport passage 4 can be lifted in a vertical direction and rollers 3 a and 4 a are provided not so as to come in contact with each other at the time of being lifted.

The first transport passage 3 and the second transport passage 4 intersecting in the crossed portion are disposed such that the intersection point thereof accords with the central axis of the turn table 2. More specifically, the first transport passage 3 and the second transport passage 4 have the same length and are disposed such that the central point thereof accords with the central axis of the turn table 2. That is, the first transport passage 3 and the second transport passage 4 rotate on the central point thereof. Further, the first transport passage 3 provided on the turn table 2 is disposed such that the first transport passage 3 is in the same straight line with the first transport rail 16 and the second transport rail 17, and the second transport passage 4 is in the same straight line with the third transport rail 18. Accordingly, when the turn table 2 rotates by about 90°, the first transport passage 3 is in the same straight line with the third transport rail 18, and the second transport passage 4 is in the same straight line with the first transport rail 16 and the second transport rail 17. Repeatedly, when the turn table 2 rotates by 90°, the first transport passage 3 is the same straight line with the first transport rail 16 and the second transport rail 17 again, and the second transport passage 4 is in the same straight line with the third transport rail 18.

The rollers 3 a and 4 a can rotate forwardly or reversely. Accordingly, even when the first transport passage 3 and the second transport passage 4 rotate and thus the directions thereof become reverse, the FOUP 5 can be transported in a regular direction by rotation of the rollers 3 a and 4 a in a reverse direction.

Additionally, the rollers 3 a and 4 a have cylinder-shaped retaining units in which the FOUP 5 is retained (not shown) and cylinder-shaped edge units which have a larger diameter than the retaining units. When the FOUP 5 is placed on a moving unit to be transported, the cylinder-shaped edge units of which the diameter is larger than that of retaining units serve as a guide, and thus the guide can prevent the FOUP 5 from being departed.

As a method of supplying electric power from the outside to a drive motor installed in the direction change device which is driven so as to rotate and an electric power motor in charge of a driving the rollers of the first and second transport passages or operating a lift unit, known methods such as a non-contact power feeding method and a slip-ring method are used, and a method of using batteries is used, if necessary.

A positional relation between the first transport passage 3 and the second transport passage 4 of the direction change device 1 which can rotate and move will be described below.

When a transport system starts or the like, the rollers 3 a of the first transport passage 3 have the same height as the rollers 13 of the transport rails 16 and 17 shown in the FIGS. 3A and 3B in a location in which the first transport rail 16 is in a straight line with the second transport rail 17 shown in FIG. 1A. The second transport passage 4 is disposed below the first transport passage 3 such that the rollers 4 a are projected from the first transport passage 3. In this manner, the FOUP 5 transported by the first transport rail 16 can be transported to the second transport rail 17 through the first transport passage 3 without interrupting the second transport passage 4.

Next, when the FOUP 5 on the first transport rail 16 is transported to the third transport rail 18 of which the transport direction is perpendicular to the transport direction of the first transport rail 16, the FOUP 5 enters from the first transport rail 16 to the first transport passage 3, and then the turn table 2 rotates with reference to FIG. 1B. Sequentially, the turn table 2 rotates by about 90°, and then the first transport passage 3 on which the FOUP 5 is placed is in a straight line with the third transport tail 18 as shown in FIG. 2A or 3C. In this manner, the FOUP 5 on the first transport passage 3 can enter the third transport rail 18.

When the first transport passage 3 is in the straight line with the third transport rail 18, the second transport passage 4 disposed perpendicularly to the first transport passage 3 is in a straight line with the first transport rail 16 and the second transport rail 17. Accordingly, the FOUP 5 on the first transport passage 3 enters the third transport rail 18, and then the first transport passage 3 descends and the second transport passage 4 ascends until the height of the rollers 4 a is the same as that of the rollers 13 with reference to FIGS. 2B and 3D. In this manner, the FOUP 5 transported by the first transport rail 16 can be carried out to the second transport passage 4. That is, such a configuration of the direction change device 1 is the same as that described in FIG. 1A.

Next, a control device 20 controlling the direction change device 1 will be described. FIG. 6 is a block diagram of a control device controlling the direction change device 1.

The control device 20 includes a control unit 21 having a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM), a rotation unit 22 rotating the turn table 2, a lift unit 23 lifting the first transport passage 3 and the second transport passage 4, a roller drive portion 24 rotating the rollers 3 a and 4 a of the first transport passage 3 and the second transport passage 4, and a sensor 25 detecting whether or not the FOUP 5 is placed on the turn table 2.

CPU of the control unit 21 executes a data table shown in FIG. 7 or a program stored in ROM to execute a process routine shown in FIG. 8, and then controls the rotation unit 22, the lift unit 23, or the roller drive unit 24.

The data table shown in FIG. 7 is used when the FOUP 5 is carried out from the first transport rail 16 to the third transport rail 18 and has a rotation angle column, a mode column, an FOUP column, a rotation direction of a roller column, and an upper and lower location column. In the rotation angle column, the rotation angles of the turn table 2, that is, 0°, 90°, 180°, 270°, are represented. When the first transport passage 3 is in the straight line with the first transport rail 16 and the second transport rail 17 on the basis of the rotation of the first transport passage 3 as shown in FIG. 1A, the rotation angle is referred to as 0° in the embodiment.

In the mode column, a carry out mode and a carry in mode are represented. The carry out mode is a mode when the FOUP 5 is transported from the turn table 2 to the third transport rail 18 and the carry in mode is a mode when FOUP 5 is transported from the first transport rail 16 to the turn table 2.

In the FOUP column, a “non-existence” and “existence” are represented. As for the “non-existence,” the FOUP 5 is not placed on the turn table 2 and as for the “existence”; the FOUP 5 is placed on the turn table 2. More specifically, when the FOUP 5 is transported from the first transport rail 16 to the approximate center of the turn table 2 in the embodiment, the sensor 25 detects the FOUP 5, and then a state of the FOUP 5 is changed from the “non-existence” to the “existence.” Additionally, when the FOUP 5 is transported from the turn table 2 to the third transport rail 18, a state of the FOUP 5 is changed from the “existence” to the “non-existence.”

The rotation direction of the roller column is divided into the first transport passage and the second transport passage columns and the rotation direction of the rollers 3 a or the roller 4 a are represented corresponding to the turn table 2. When the rotation angle is “0°”, a direction rotated such that the FOUP 5 is transported from the first transport rail 16 to the second transport rail 17 is referred to as a “forward” direction of the rollers 3 a. That is, when the rotation angle is “180°”, the rotation direction of the roller 3 a is referred to as “reverse”. Accordingly, the FOUP 5 is transported in the same direction as the rotation direction of which the roller is “forward” when the rotation angle is “0°.” Additionally, when the rotation angle is “90°,” a direction rotated such that the FOUP 5 is transported from the first transport rail 16 to the second transport rail 17 is referred to as a “forward” direction of the rollers 4 a. A sign “−” in the table means that the roller does not rotate. As described below, the rollers 3 a and 4 a do not rotate at the time the turn table 2 is rotating.

The upper and lower location column is divided into the first transport passage and the second transport passage columns and locations of the first transport passage 3 and the second transport passage 4 in the rotation angles of the turn table 2 are represented. The “upper” means a location in which the height of the rollers 3 a or 4 a is the same as that of the rollers 13 of the transport passages 16, 17 and 18, and the “lower” means a location in which the rollers 3 a or 4 a are not projected from the rollers 3 a or 4 a on the “upper”. For example, when the rotation angle is “0°” and FOUP is in the “non-existence,” the first transport passage 3 is in the “upper” location and the second transport passage 4 is in the “lower” location in terms of the location relationship between the first transport passage 3 and the second transport passage 4.

Operation of Control Device

Next, when the FOUP 5 on the first transport rail 16 enters the third transport rail 18, an operation of the direction change device 1 will be described below.

In a routine of processing a direction change shown in FIG. 8, in the first place, a rotation angle of a turn table 2 are acquired on the basis of a first transport passage 3 (SI) Rollers of a transport passage are driven on the basis of the acquired rotation angle and the data table of FIG. 7 (S2). Specifically, when the rotation angle is “0°” and the mode is “carried out mode,” rollers 3 a of the first transport passage 3 forwardly rotate. In this case, rollers 4 a of a second transport passage 4 do not rotate.

Next, it is determined whether or not the FOUP 5 placed on the turn table 2 (S3). Specifically, it is determined whether or not the FOUP 5 enters from the first transport rail 16 to the center of the first transport passage 3. When the FOUP 5 is not placed on the turn table (S3: NO), S3 is reiterated, When the FOUP 5 is placed on the turn table (S3: YES), the rotation of the rollers 3 a stops (S4) and the turn table 2 rotates by about 90° (S5). In this case, the FOUP 5 can be transported on the first transport passage 3 while the turn table is rotating.

Sequentially, by rotating the turn table 2 by 90°, the first transport passage 3 is in a straight line with the third transport rail 18 before the rollers 3 a rotate again (S6). Continuously, it is determined whether or not the FOUP 5 is placed on the turn table 2 (S7). That is, it is determined whether or not the FOUP 5 on the first transport passage 3 is transported to the third transport rail 18. When the FOUP 5 is placed on the turn table 2 (S7: NO), S7 is reiterated. When the FOUP 5 is not placed on the turn table 2 (S7: YES), the rotation of the rollers 3 a stops (S8), and the first transport passage 3 descends and the second transport passage 4 ascends to exchange height positions of the first transport passage 3 and the second transport passage 4 each other (S9). Thereafter, the above-described operation is reiterated from S1.

Overview of the Embodiment

As described above, a direction change device 1 which changes a transporting direction of the FOUP 5 carried out from a first transport rail 16 transporting the FOUP 5, the direction change device includes a first transport passage 3 and second transport passage 4 having a straight-line shape and the same length, in which one of the transport passages is disposed at the same vertical position as that of the first transport rail 16, the other transport passage is disposed below the one transport passage, and they intersect each other with a right angle so that central points thereof are on the same vertical line, thereby transporting the FOUP 5 along the transport passages; a rotating unit 22 rotating the first transport passage 3 and second transport passage 4 about the central point; a lift unit 23 lifting the first transport passage 3 and second transport passage 4 in a vertical direction; and a control unit 21 rotating the first transport passage 3 and second transport passage 4 by about 90° when the FOUP 5 is carried out from the transport rail to the transport passage disposed at the same vertical position as that of the first transport rail 16, so that the FOUP 5 is removed from the transport passage and exchanging the respective vertical positions of the first transport passage 3 and second transport passage 4.

In such a configuration, after the direction of the FOUP 5 is changed to remove the FOUP 5, the next the FOUP 5 can be ready to change the direction thereof in a short time. Specifically, by equalizing the heights of the first transport passage 3 and the first transport rail 16 and disposing the second transport passage 4 vertically to the first transport passage 3 below the first transport passage 3, the FOUP 5 of the first transport rail 16 can be removed to the first transport passage 3 without interrupting the second transport passage 4. Additionally, when the FOUP 5 are carried out from the first transport rail 16 to the first transport passage 3, the direction on the FOUP 5 can be changed by 90° by rotating the first transport passage 3 and second transport passage 4 by about 90°. After the FOUP 5 is carried out from the first transport passage 3, the FOUP 5 of the first transport rail 16 can be removed to the second transport passage 4 by changing locations of the vertical directions of the first transport passage 3 and second transport passage 4 each other.

That is, when only one transport passage is provided in the rotation unit, the FOUP 5 is removed by rotating the transport passage, and then the transport passage is required to rotate from the first transport rail 16 again to a location in which the FOUP 5 can be carried out. However, as described above, by exchanging the positions of the vertical directions of two transport passages, an idle time can be shortened.

Additionally, the first transport rail 16 and the first transport passage 3 and second transport passage 4 according to the invention have a plurality of rollers 3 a and 4 a capable of rotating along both sides of the transport passages, and can transport the FOUP 5 placed on the rollers by rotation of the rollers.

In such a configuration, since the FOUP 5 is transported by rotation of the first transport rail 16 and the rollers provided along both sides of the transport passages, the FOUP S can be transported without interrupting the direction of the FOUP 5.

Modification Embodiment

The above-described preferred embodiment of the invention is described, but the invention is not limited to the described embodiment. The invention may be modified in various forms without departing from the gist of the invention. Further, according to the embodiment, the operation and advantage of the configuration of the invention is described above, but the operation and advantage are just an example and the invention is not limited thereto.

For example, when the FOUP 5 is placed on the first transport passage 3, the rotation of the roller 3 a of the first transport passage 3 stops and the turn table 2 rotates according to the embodiment. However, while the FOUP S is transported, the turn table 2 may rotate. In this case, since the FOUP 5 can be transported from the first transport rail 16 to the third transport rail 18 without stopping the FOUP 5 on the first transport passage 3, a time required to change the direction may be shortened more. Additionally, it is described that the direction change device 1 is disposed in the three sides “T-shaped” intersection, but the direction change device 1 is not limited to the above-described intersection and may be provided in a location in which two transport rails or more are intersected.

Additionally, in the direction change device 1, the FOUP 5 is transported by rotation of the rollers 3 a and 4 a, but may be transported by a belt conveyor, for example. Further, a method of transporting the FOUP 5 is not limited to the above-described embodiment. 

1. A direction change device which changes transporting direction of a work carried out from a transport rail, comprising: first and second transport passages that has a straight-line shape, and are disposed so that they intersect each other with a right angle and central points thereof are on the same vertical line; a rotating unit that rotates the first and second transport passages about the central point; a lift unit that lifts the first and second transport passages in a vertical direction; and a control unit, wherein a vertical position of one of the first and second transport passages is made the same as that of the transport rail, and other of the first and second transport passages is made lower than that of the one of the first and second transport passages, and the control unit controls such that: carrying in the work from the transport rail to one of the first and second transport passages of which vertical position is the same as a vertical position of the transport rail, rotating the first and second transport passages about 90°; carrying out the work from the one of the first and second transport passages; and exchanging the vertical positions of the first and second transport passages each other.
 2. The direction change device according to claim 1, wherein the transport rail and the first and the second transport passages have a plurality of rollers along with both sides thereof, and the work placed on the rollers is transported by rotation of the rollers. 